Antifreeze/coolant formulations containing inorganic silicates as corrosion inhibitors have a tendency to form an irreversible gel after a period of time. Stabilizers improve the gelation resistance of these coolant formulations. The use of organic polysiloxanes to stabilize the inorganic silicates used as corrosion inhibitors in antifreeze/coolant formulations is known in the prior art as is illustrated by U.S. Pat. Nos. 4,462,921 and 4,485,025.
In U.S. Pat. No. 4,462,921, there is disclosed the use of a glycol soluble organosiloxane polymer having the formula EQU (CH.sub.3).sub.3 --Si--O--[SiRCH.sub.3 --O].sub.n --Si(CH.sub.3).sub.3
where n is an integer from 1 to 20 and R is selected from the group consisting of a cyano-terminated moiety, a diol ether moiety, a carboxylic acid moiety and an amide moiety.
In U.S. Pat. No. 4,485,025, there is disclosed the use of a glycol soluble organosiloxane polymer having the formula EQU R--[Si(R).sub.2 --O].sub.n --SiR.sub.x --[OR'].sub.(3-x)
where R is an alkyl, alkoxy or a solubilizing moiety selected from the group consisting of a cyano-terminated moiety, a diol ether moiety, a carboxylic acid moiety and an amide moiety, R' is an alkyl, aryl, alkaryl or acyl group, x is an integer from 0 to 3 and n ranges from 1 to 5.
Both '921 and '025 claim the use of the respective organosiloxane polymers at levels of about 0.01 to 1 weight percent to prevent gelation of the organic silicates in antifreeze/coolant formulations.